But be forewarned. A good room addition involves a whole lot more than just slapping on some additional square footage. Here are some important rules to keep in mind as your planning gets under way:
1. Know why you're adding on: This is the first rule, and it happens before you lift a hammer. Why do you need to add on? And no fair cheating and saying, "I need more space!"
Do you need another bathroom? Bedroom space? A laundry room or mud room? An improved kitchen flow? More space to entertain? Better accessibility due to health issues? More storage? A larger garage or hobby area? The only way the addition will meet your needs is to know what those needs are in the first place.
2. Good additions never look like additions: This is the other top rule of room-addition planning. When you're done, the addition -- no matter what its size or where it's located -- should never look like an addition. The architectural styles of new and existing need to blend.
The exterior materials need to blend as well, or at least complement each other. To the extent possible, use the same type of windows, roofing, doors, siding and other materials. If the original home has wood windows, using new vinyl windows in the addition screams "add-on" and lowers the appeal and the value. Don't overlook the need to blend landscaping and hardscaping as well.
3. Out, up, down, or a combination: The how and the where of a room addition is always a fun and exciting challenge for everyone involved. Some homes are situated on larger lots and lend themselves very nicely to adding out. Others seem best suited to adding up by building on a second or even a partial third floor.
Some houses are even laid out in such a way that it's possible to excavate under them and add new living space in the form of a daylight basement. Or it could be that a combination of two or even all three of these options makes the most sense for your particular home.
Keep your mind open to the possibilities. Work with a good contractor and a good designer and you'll be amazed at what you can come up with.
4. Don't let the interior become an afterthought: I've seen a surprising number of additions that look great from the outside but seem to have no thought put into them on the inside. Flooring doesn't match. Trim doesn't match. Sometimes even the interior floor heights don't match. Remember that how the interior of your addition looks and flows on the inside is just as important as how it looks and flows on the outside.
Use the same materials or the same style of materials. Match up ceiling, floor, and wall levels. Here again, no matter how you view the addition, inside or out, it should never look like an addition.
5. Create convenient access: This is another afterthought in a lot of additions. Let's say you have a three-bedroom, one-bathroom house, and you want to add a second bathroom. Typically, that's an addition that's going to have a good payback.
But then you build the addition so that the only access to the second bathroom is through the kitchen. You now have a three-bedroom, two-bath house, but since the layout is lousy, you've actually gone backwards in terms of desirability and resale value.
Are you going to create a beautiful second-floor master suite that can be accessed only by a tiny spiral staircase from the family room? Is the only way into your great new kitchen via a convoluted hallway that leads through the laundry room?
When planning your addition, never lose sight of how you're going to access the new spaces, and make sure that access is both convenient and inviting.
6. Don't overwhelm your lot: Granted, room additions are expensive. So when you're doing one, and all those workers are onsite, there's a temptation to get as much square footage as you can. But don't cram your lot full of house. Remember that open space is important as well, both to you and your family, and, later on, to potential buyers.
This is a good time to go back to Rule No. 1 and reconsider the "why" part of your room addition. Don't add space just to add it -- stay focused on your overall goals.
7. Understand the legalities: There are lots of rules and regulations that come into play regarding room additions. These include property line setbacks, zoning restrictions, and restrictions imposed by homeowner associations and architectural review committees.
In some historic areas, your addition may have to comply with certain historic guidelines. In other areas, there may even be solar shading restrictions that limit the height or the orientation of your roof line. Be sure you check into all of this before you get too far along with your planning.